Dr. S. Patrick Donegan, under Dr. Rice's supervision, will direct the Clinical core that will provide subjects including patient materials and epidemiologic information to each of the Projects to advance their scientific questions. The core patient groups will consist of women who are enrolled in in vitro fertilization programs at Brigham and Women's hospital, women who undergo endometrial biopsies at the BCH-STD-Clinic for suspected endometritis, and BCH-STD attendees who will enroll in behavioral intervention studies.